KR101747441B1 - Hyaluronic Acid-Based Gels Including Anesthetic Agents - Google Patents

Abstract

Soft tissue fillers, e. G., Skin and subcutaneous fillers, based on hyaluronic acid and its pharmaceutically acceptable salts are disclosed herein. In one aspect, the hyaluronic acid-based compositions described herein comprise a therapeutically effective amount of at least one anesthetic, for example, lidocaine. For example, the hyaluronic acid-based compositions of the present invention, including lidocaine, upon exposure to sterile techniques or for extended periods of storage, have improved stability compared to conventional compositions comprising lidocaine. Methods and processes for making such hyaluronic acid-based compositions are also provided.

Description

Hyaluronic Acid-Based Gels Including Anesthetic Agents < RTI ID = 0.0 >

Cross reference of related application

This application is related to US Provisional Patent Application No. 61 / 085,956, filed on August 4, 2008, US Provisional Patent Application No. 61 / 087,934, filed on August 11, 2008, US Provisional Patent Application Filed on February 26, 2009, and U.S. Serial No. 12 / 393,884, filed February 26, 2009, which are incorporated herein by reference in their entirety, Is incorporated by reference in its entirety.

Field of invention

The present invention relates generally to soft tissue fillers and, more particularly, to hyaluronic acid-based skin and subcutaneous fillers comprising an anesthetic agent

As people grow older, the effects of long-term facial muscle movements such as gravity, daylight-exposure, and laughing, grimacing, chewing, and thinning of the eyes, appear on the face. The underlying tissue that keeps the skin looking younger begins to break down and often results in a laugh line, a smile line, a "crow's feet" and a facial crease, It is often called the "effects of aging".

In an effort to cure or correct the effects of aging, soft tissue fillers have been developed to help fill facial wrinkles and depressions and restore fat loss-related tissue volume losses. Whereby the soft tissue filler is temporarily smooth, restoring a younger appearance.

Ideally, soft tissue fillers are long-lasting, soft, smooth, and natural appearance when implanted in or under the skin. In addition, the soft tissue filler is easy to implant into a patient using a fine gauge needle and has little extrusion force required for injection. The ideal filler also does not cause any harmful side effects, and can be injected with minimal or no discomfort to the patient.

Collagen-based soft tissue fillers have been developed more than 20 years ago, and for a time, bovine collagen-based fillers were the only skin fillers approved by the US Food and Drug Administration (FDA). Because these skin lesions are based on cows, one of the main disadvantages was the possibility of an allergic response in the patient. Approximately 3 to 5% of human subjects are believed to exhibit a severe allergic response to bovine collagen and careful testing is therefore required prior to use of such a filler on any person skilled in the art. In addition to allergic reactions, collagen-based fillers dissolve quickly upon injection, requiring frequent treatment to maintain a smoother, younger appearance.

In February 2003, the human-derived collagen filler composition was FDA approved. These collagens offer the advantage of significantly reducing the risk of allergic reactions. However, despite the reduced occurrence of allergic reactions, the human-derived collagen fillers still suffer from rapid degradation of the injected product.

Studies on fillers that continue to smoother and younger appearances without causing allergic reactions have led to the development of hyaluronic acid (HA) -based products. In December 2003, the first HA-based filler was approved by the FDA. The development of other HA-based fillers followed quickly.

HA, also known as hyaluronan, is a natural, water-soluble polysaccharide, in particular glucosaminoglycan, the major component of the extra-cellular matrix and is widely distributed in animal tissues. HA has excellent biocompatibility and does not cause an allergic reaction when implanted in a patient. In addition, HA is an excellent volumizer of soft tissues because it has the ability to bind large amounts of water.

The development of HA-based fillers that exhibit ideal in vivo properties as well as ideal surgical usability has proved difficult. For example, an HA-based filler exhibiting desirable stability properties in vivo may be highly viscous such that injection through a micro gauge needle is difficult. Conversely, HA-based fillers that are easily injected through relatively fine gauge needles are often inferior in in vivo stability properties.

One way to overcome this problem is to use a crosslinked HA-based filler. The crosslinked HA is formed by reacting free HA with a crosslinking agent under suitable reaction conditions. Methods of making HA-based soft tissue fillers comprising both crosslinked HA and free HA are well known.

It has been proposed to incorporate certain therapeutic agents, for example anesthetics such as lidocaine, into injectable HA-based compositions. Unfortunately, HA-based injectable compositions incorporating lidocaine during the manufacturing process tend to be partially or substantially completely degraded prior to injection, particularly during the hot sterilization step, and / or when stored for any fairly long period of time.

The aim of the HA-based soft tissue filler composition described herein, and its method of manufacture and use, is to provide a soft tissue filler that does not cause an allergic reaction in a patient, is biocompatible, stable in vivo and useful, and includes one or more topical anesthetics .

Figure 1 shows a graph of lidocaine concentration in gel from sample 5 of Example 4 prepared by the procedure of Test 2 over time.

summary

The present invention relates to skin and subcutaneous fillers based on soft tissue fillers such as, for example, hyaluronic acid (HA) and pharmaceutically acceptable salts of HA, for example sodium hyaluronate (NaHA). The HA-based compositions described herein comprise a therapeutically effective amount of at least one anesthetic. In one embodiment, for example, the anesthetic is lidocaine. The HA-based compositions of the present invention comprising at least one anesthetic can be used in a variety of ways, including when exposed to sterilization techniques such as autoclaving, and / or when stored at ambient temperature for extended periods of time, Gt; HA-based < / RTI > composition. Methods of making such HA-based compositions and articles made by such methods are also provided.

Soft tissue filler compositions are also described herein and are generally prepared from 1,4-butanediol diglycidyl ether (BDDE), 1,4-bis (2,3-epoxypropoxy) butane, Bis (2,3-epoxypropoxy) ethylene and 1- (2,3-epoxypropyl) -2,3-epoxycyclohexane, and 1,4- Crosslinked hyaluronic acid (HA) component with a crosslinking agent selected from the group consisting of butanediol diglycidyl ether; And at least one anesthetic in combination with a cross-linked HA component.

In another embodiment, the at least one anesthetic is lidocaine. In another embodiment, the amount of anesthetic is present at a concentration of from about 0.1% to about 5.0% by weight of the composition. In another embodiment, the anesthetic is present at a concentration of from about 0.2% to about 1.0% by weight of the composition. In one embodiment, the anesthetic is lidocaine and is present at a concentration of about 0.3% by weight of the composition.

In yet another embodiment, the soft tissue filler composition has a pressure output of from about 10 N to about 13 N, for example, at a rate of about 12.5 mm / min. In another embodiment, the composition has a viscosity of, for example, about 5 Pa * s to about 450 Pa * s as measured at about 5 Hz.

In one embodiment, the HA component is a gel, for example a cohesive, hydrated gel. In one embodiment, the HA component is a crosslinked HA gel having from about 1% to about 10% free HA. For the purposes of the present invention, free HA includes both HA chains and fragments which are slightly cross-linked as well as uncrosslinked HA, all in a water soluble form.

In another embodiment, the HA component comprises greater than about 10%, such as greater than about 15%, such as up to about 20% or greater than about 20% free HA.

In another embodiment, the HA component is a gel comprising particles of cross-linked HA in a medium that is relatively fluid of free HA. In some embodiments, the HA component has an average particle size of greater than about 200 microns, for example, greater than about 250 microns.

HA component crosslinked with 1,4-butanediol diglycidyl ether (BDDE), wherein the HA component has a crosslinking degree of less than about 5%, for example about 2%, and the concentration is less than about 5% A soft tissue filler composition comprising an anesthetic component-an anesthetic agent that is lidocaine-about 0.1 wt% to about 5.0 wt% of the composition is also described herein.

Butadiene diglycidyl ether (BDDE), 1,4-bis (2,3-epoxypropoxy) butane, 1,4-bisglycidyloxybutane, 1,2-bis , 3-epoxypropoxy) ethylene and 1- (2,3-epoxypropyl) -2,3-epoxycyclohexane, and 1,4-butanediol diglycidyl ether, or combinations thereof. Providing a crosslinked HA component with at least one crosslinking agent; Adjusting the pH of the HA component to a regulated pH of greater than about 7.2; And adding at least one anesthetic agent to a HA component having a controlled pH to obtain an HA-based filler composition, is also described herein.

In another embodiment, the composition is sterilized, for example, by autoclaving, to form a sterilized composition, and the sterilized composition is maintained at ambient temperature for at least about 6 months, e.g., for at least 9 months, It is stable for about 12 months or longer.

In another embodiment, the controlled pH is greater than about 7.5. In another embodiment, the method further comprises homogenizing the HA component during or after adding the solution containing at least one anesthetic agent. In a further embodiment, homogenizing comprises mixing the composition with a controlled shear.

In another embodiment, providing the HA component comprises providing a dry-free NaHA material and hydrating the dry-free NaHA material in an alkali solution to obtain an alkali, free NaHA gel. In another embodiment, the alkali, free NaHA gel has a pH of greater than about 8.0. In another embodiment, the pH is greater than about 10.

In a further embodiment, the HA component comprises greater than about 20% free HA and the crosslinked portion of the HA component has a degree of crosslinking of less than about 6% or less than about 5%.

In yet another embodiment, the soft tissue filler composition has particulate properties in that it comprises particles of cross-linked HA dispersed in a flowable soluble HA medium. In some embodiments, the average size of such particles is at least about 200 microns, and in other embodiments, the average size of such particles is at least about 250 microns.

A hyaluronic acid (HA) component crosslinked with 1,4-butanediol diglycidyl ether (BDDE), the HA component having a crosslinking degree of less than about 5%, and a concentration of about 0.1 Wt.% To about 5.0 wt.% Of an anesthetic component-an anesthetic agent is lidocaine is also described herein.

In certain embodiments of the present invention, a method of making a soft tissue filler composition is also described, the method comprising: providing a dry-free NaHA material; and hydrating the dry-free NaHA material in an alkali solution to obtain an alkali, free NaHA gel; Crosslinking the free NaHA gel with BDDE to form a crosslinked alkali HA composition having a degree of crosslinking of less than about 5% and a pH of greater than about 7.2; Adding a solution containing 0.3% lidocaine HCl to the HA component having a controlled pH to obtain an HA-based filler composition; Homogenizing the HA-based filler composition to form a homogenized HA-based filler composition; And forming a sterilized HA-based filler composition by sterilizing the homogenized HA-based filler composition, wherein the soft tissue filler composition has a particle size greater than about 200 microns, e.g., the particle size is greater than about 250 microns .

Justice

As used herein, certain terms are intended to refer to the following definitions as described below. Where the definition of a term differs from the meaning of a commonly used term, the applicant wishes to use the definition provided below unless specifically stated otherwise.

As used herein, "autoclave stability" or "stable to autoclaving" refers to a product that is resistant to degradation so that the product or composition retains at least one, and preferably all, of the following characteristics after effective autoclave sterilization Or composition of matter: transparent appearance, pH, pressure output and / or rheology, hyaluronic acid (HA) concentration, sterility, osmolarity, and lidocaine concentration.

As used herein, a high molecular weight HA refers to a HA material having a molecular weight of at least about 1.0 million daltons (mw ≥ 10 ⁶ Da or 1 MDa) to about 4.0 MDa. For example, the high molecular weight HA in the composition of the present invention may have a molecular weight of about 2.0 MDa. In another example, the high molecular weight HA may have a molecular weight of about 2.8 MDa.

As used herein, a low molecular weight HA refers to an HA material having a molecular weight of less than about 1.0 MDa. Low molecular weight HA has a molecular weight of less than about 200,000 Da (0.2 MDa) to less than about 1.0 MDa, for example, about 300,000 Da (0.3 M Da) to about 750,000 Da. (0.75 MDa).

The degree of crosslinking as used herein refers to the degree of crosslinking of individual HA polymer molecules, or monomer chains, to a permanent structure, or to an intermolecular junction that links the soft tissue filler composition as described herein it means. Moreover, for purposes of the present invention, the degree of crosslinking is also defined as the weight percent of crosslinking agent to HA-monomer units in the crosslinked portion of the HA-based composition. This is measured as the weight ratio of the HA monomer to the crosslinking agent (HA monomer: crosslinking agent).

As used herein, the free HA is a highly crosslinked (higher crosslinked) macromolecular structure that constitutes a soft tissue filler composition, either a non-crosslinked or very slightly crosslinked individual HA Quot; refers to a polymer molecule. Free HA generally remains water-soluble. Free HA may alternatively be defined as a "non-crosslinked" or slightly crosslinked component of the macromolecular structure that constitutes the soft tissue filler composition described herein.

Cohesion as used herein refers to the ability of an HA-based composition to maintain its shape and resist deformation. Cohesion is affected by the molecular weight ratio, the degree of crosslinking, the amount of residual free HA after crosslinking, and the HA-based composition pH, among other factors. The coherent HA-based composition is resistant to phase separation in testing according to the method disclosed in Example 1 herein.

details

The present invention relates generally to skin and subcutaneous fillers based on soft tissue fillers such as, for example, hyaluronic acid (HA) and pharmaceutically acceptable salts of HA, for example sodium hyaluronate (NaHA). In one aspect, the HA-based compositions described herein comprise a therapeutically effective amount of at least one anesthetic, for example, lidocaine. The HA-based compositions of the present invention comprising at least one anesthetic agent can be used in a variety of applications, such as on exposure to high temperatures and high pressures, for example, upon exposure to heat and / or pressure sterilization techniques, such as autoclaving, and / For example, lidocaine, when stored at ambient temperatures for extended periods of time, as compared to conventional HA-based compositions.

The stable composition maintains at least one or both of the following characteristics after effective autoclave sterilization and / or long term storage: transparent appearance, pH for use in patients, pressure output and / or rheology characteristics, HA concentration, sterility , Osmotic concentration, and lidocaine concentration. Products and processes for making such HA-based compositions as well as products made by such processes or processes are also provided.

As used herein, hyaluronic acid (HA) refers to any hyaluronic acid salt thereof, including but not limited to sodium hyaluronate (NaHA), potassium hyaluronate, magnesium hyaluronate, potassium hyaluronate, and combinations thereof Do not.

Generally, the concentration of HA disclosed herein is preferably at least 10 mg / mL and at most about 40 mg / mL. For example, the concentration of HA in some compositions ranges from about 20 mg / mL to about 30 mg / mL. Also, for example, in some embodiments, the composition has an HA concentration of about 22 mg / mL, about 24 mg / mL, about 26 mg / mL, or about 28 mg / mL.

In addition, the concentration of one or more anesthetic agents is an amount effective to alleviate the pain experienced during injection of the composition. At least one topical anesthetic is selected from the group consisting of ambucaine, amolanone, amylocaine, benoxinate, benzocaine, betoxycaine, biphenamine, bupivacaine, butacaine, butamben, butanilicaine, butethamine, butoxycaine, carticaine, chloroprofen, But are not limited to, chloroprocaine, cocaethylene, cocaine, cyclomethycaine, dibucaine, dimethysoquin, dimethocaine, diperodon ), Dicyclonine, ecgonidine, ecgonine, ethyl chloride, etidocaine, beta-eucaine, euprocin, ), Fenalcomine, formocaine, hexylcaine, hydroxysteine, But are not limited to, hydroxytetracaine, isobutyl p-aminobenzoate, leucinocaine mesylate, levoxadrol, lidocaine, mepivacaine, But are not limited to, meprylcaine, metabutoxycaine, methyl chloride, myrtecaine, naepaine, octacaine, orthocaine, oxeta The compounds of the present invention can be used in combination with other drugs such as oxethazaine, parethoxycaine, phenacaine, phenol, piperocaine, pyridocaine, polidocanol, pramoxine, But are not limited to, prilocaine, procaine, propanocaine, proparacaine, propipocaine, propoxycaine, psuedococaine, pyrrocaine, ), Ropivacaine, salicyl alcohol, Can be selected from the group consisting of tetracaine, tolycaine, trimecaine, zolamine, and salts thereof. In one embodiment, at least one anesthetic is in the form of a lidocaine, such as lidocaine HCl. The compositions described herein can be from about 0.1% to about 5% by weight of the composition, for example from about 0.2% to about 1.0% by weight of the composition, of lidocaine. In one embodiment, the composition has a lidocaine concentration of about 0.3% (w / w%) of the composition. The concentration of lidocaine in the compositions described herein may be therapeutically effective, which means a concentration suitable to provide therapeutic benefit without being detrimental to the patient.

In one aspect of the present invention, there is provided a method of making an HA-based composition comprising an effective amount of lidocaine, the method comprising the steps of providing a precursor composition further comprising a coherent crosslinked HA-based gel, For example, adding thereto a solution containing lidocaine in the form of lidocaine HCl; And homogenizing the mixture to obtain a coherent, at least partially crosslinked, HA-based composition comprising lidocaine that is stable to autoclaving. Cohesive, cross-linked HA-based gels contain from about 1% to about 10% by weight of free HA material or less cross-linked HA material.

Although not intending to be limited to any particular theory of action, in some embodiments of the present invention, the highly coherent precursor composition will substantially or totally prevent or prevent any destruction or degradation of cross-linked HA in the lidocaine- It is believed to work to interfere.

It is believed that such degradation can occur predominantly because many, perhaps most, crosslinked HA-based gels are routinely produced in a manner that produces gels that are not sufficiently coherent to prevent such degradation when lidocaine is added. The addition of lidocaine to a sufficiently cross-linked HA-based composition does not result in substantial or significant composition degradation, and even during prolonged storage, for example, for a period of at least 6 months to over a year, and during sterilization procedures, , It has been found that the composition maintains its integrity in terms of rheology, viscosity, appearance and other properties even after exposure to autoclaving.

It is a surprising discovery that a formulation of a cross-linked HA-based composition comprising lidocaine can be produced in a manner consistent with the present invention to produce a sterile-stable, injectable HA / lidocaine composition.

A cohesive, cross-linked HA-based precursor composition is prepared, lidocaine hydrochloride is added to the precursor composition to form a HA / lidocaine gel mixture and the mixture is homogenized to obtain a stable crosslinked HA-based composition for autoclaving , A method of making a stable HA-based composition containing an effective amount of lidocaine is also described herein.

In certain embodiments, the precursor composition is a gel comprising less than about 1% by weight solubility-liquid form or free HA. In another embodiment, the precursor composition comprises from about 1% to about 10% by weight of free HA.

The precursor composition comprises a first component comprising relatively highly crosslinked HA particles that are substantially solid phase and a second component comprising relatively free crosslinked HA particles in a substantially fluidic phase in which relatively highly crosslinked particles are dispersed, And a second component comprising bound HA. The composition may comprise from about 10% to about 20% by weight of free HA.

In some embodiments, the free HA constitutes less than 20% by weight of the composition. For example, free HA constitutes less than 10% by weight of the HA component. In a further example, the second portion comprises from about 1% to about 10% by weight of the HA component.

For example, the precursor composition may comprise a coherent, HA-based gel.

In another embodiment, the free HA constitutes more than about 20% by weight of the HA component.

In some embodiments, the compositions of the present invention have particulate properties and include relatively highly cross-linked HA particles dispersed in a medium of relatively less cross-linked HA. In some embodiments, the average size of such particles of cross-linked HA is at least about 200 占 퐉 or at least about 250 占 퐉. Such a particulate composition is generally less cohesive than a similar composition with no particles or with particles having an average size of less than 200 [mu] m.

For example, in some embodiments, the precursor composition may be prepared by pushing through a sieve or mesh of agglomerates of relatively highly cross-linked HA-based gels to produce relatively highly cross-linked HA particles of generally uniform size and shape . These particles are then mixed with a carrier material, for example, a certain amount of free HA to form a gel.

Also provided is a method of making an HA-based composition comprising an effective amount of lidocaine, the method comprising providing a precursor composition comprising a substantially pH neutral, at least partially cross-linked HA-based gel, To a pH of greater than about 7.2, for example, from about 7.5 to about 8.0. The method comprises combining the solution containing the lidocaine, for example in the form of a lidocaine HCl, with a gel which is more or less alkaline, after the pH is thus adjusted, and obtaining an HA-based composition comprising a stable lidocain in autoclaving .

Another method of producing a stable HA-based composition containing an effective amount of lidocaine comprises: providing a purified NaHA material, e.g. in the form of a fiber, as described elsewhere herein; Hydrating the material; And crosslinking the hydrated material with a suitable cross-linking agent to form a cross-linked HA-based gel. The method further comprises neutralizing and expanding the gel, and adding a solution containing an acidic salt of lidocaine, preferably lidocaine hydrochloride, to the gel to form a HA / lidocaine gel. In addition, the present invention further comprises homogenizing the HA / lidocaine gel and packaging the homogenized HA / lidocaine gel, for example, in a syringe for dispensing. The syringe is then sterilized by autoclaving at an effective temperature and pressure. According to the present invention, packaged and sterilized cohesive NaHA / lidocaine gels exhibit improved stability compared to HA-based compositions comprising lidocaine prepared using conventional methods.

The articles of manufacture and compositions of the present invention can be applied to autoclaving for a period of at least about 1 minute to about 15 minutes at a temperature of at least about 120 DEG C to about 130 DEG C and / or at least about 12 pounds per square inch (PSI) It is believed to be sterilized upon exposure to pressure.

The product or composition of the present invention is also kept stable for long term storage at room temperature. Preferably, the compositions of the invention are stable at a temperature of at least about 25 占 폚 for a period of at least about 2 months, or at least about 6 months, or at least about 9 months, or at least about 12 months, or at least about 36 months maintain. In certain embodiments, the composition is stable for a period of at least 2 months at a temperature of at most about 45 ° C.

In one embodiment, the manufacturing process comprises an initial step of providing the raw HA material in the form of a dry HA fiber or powder. The raw HA material may be HA, its salt and / or a mixture thereof. In a preferred embodiment, the HA material comprises NaHA, and even more preferably, a fiber or powder of bacterial-sourced NaHA. In some aspects of the invention, the HA material may be derived from an animal. The HA material may be a combination of raw materials including HA and at least one other polysaccharide, for example, glycosaminoglycan (GAG).

In some embodiments, the HA material in the composition is composed or entirely composed of a high molecular weight HA. That is, almost 100% of the HA material in the composition of the present invention may be a high molecular weight HA as defined above. In another embodiment, as defined above, the HA material in the composition comprises a combination of a relatively high molecular weight HA and a relatively low molecular weight HA.

The HA material of the composition may comprise from about 5% to about 95% high molecular weight HA and the remainder of the HA material is low molecular weight HA. In an exemplary embodiment of the invention, the ratio of high molecular weight HA to low molecular weight HA is at least about 2, preferably more than 2 (w / w 2), and the high molecular weight HA has a molecular weight of more than 1.0 MDa.

The selection of high molecular weight HA and low molecular weight HA materials and their relative percentages or ratios will depend on the desired properties of the final HA-based product, such as the power output, elastic modulus, viscous modulus, It will be understood by those skilled in the art that depending on the phase angle, cohesion, etc. expressed as the ratio of the viscous modulus to the modulus. For additional information that may help to understand these and other aspects of the present invention, reference is made to Lebreton, US Patent Application Publication 2006/0194758, which is incorporated herein by reference in its entirety.

HA-based gels can be prepared according to the present invention by first cleaning and purifying dry or raw HA materials having the required high molecular weight / low molecular weight ratio. These steps include, for example, hydration of the dried HA fibers or powder with the required high molecular weight / low molecular weight ratio, using pure water, and filtering the material to remove large contaminants and / or other impurities It is accompanied. The filtered and hydrated material is then dried and purified. The high molecular weight HA and low molecular weight HA can be separately cleaned and purified, or just prior to crosslinking, for example, mixed together at the desired ratio.

In one aspect of the invention, pure, dry NaHA fibers are hydrated in an alkaline solution to produce free NaHA alkaline gel. Any suitable alkaline solution of, for example, but not limited to, sodium hydroxide (NaOH), potassium hydroxide (KOH), sodium bicarbonate (NaHCO _3), the aqueous solution containing lithium hydroxide (LiOH), etc. NaHA at this stage Can be used to hydrate. In another embodiment, a suitable alkaline solution is an aqueous solution containing NaOH. The resulting alkaline gel will have a pH of greater than 7.5. The pH of the resulting alkaline gel may be a pH greater than 9, or greater than 10, or greater than 12, or greater than 13.

The next step in the manufacturing process involves cross-linking the hydrated, alkali NaHA gel with a suitable cross-linking agent. The crosslinking agent may be any agent known to be suitable for crosslinking polysaccharides and derivatives thereof via hydroxyl groups. Suitable cross-linking agents include 1,4-butanediol diglycidyl ether (or 1,4-bis (2,3-epoxypropoxy) butane or 1,4-bisglycidyloxybutane, Bis (2,3-epoxypropoxy) ethylene and 1- (2,3-epoxypropyl) -2,3-epoxycyclohexane. The use of more than one crosslinking agent or a different crosslinking agent is not excluded from the scope of the present invention. In one aspect of the present invention, the HA gel described herein is crosslinked using BDDE.

The crosslinking step may be carried out using any means known to those skilled in the art. Those skilled in the art will know how to optimize crosslinking conditions and how to perform crosslinking to an optimized degree depending on the nature of the HA.

For purposes of the present invention, the degree of crosslinking is defined as the weight percent of cross-linking agent to HA-monomer units in the cross-linked portion of the HA-based composition. This is measured by the weight ratio of HA monomer to crosslinking agent (HA monomer: crosslinking agent).

The crosslinking degree in the HA component of the present invention is at least about 2% and at most about 20%.

In some embodiments, the degree of crosslinking is from about 4% to about 12%. In some embodiments, the degree of crosslinking is less than about 6%, for example less than about 5%.

In another embodiment, the degree of cross-linking is greater than 5%, for example from about 6% to about 8%.

In some embodiments, the HA component is capable of absorbing at least about one time its weight of water. When neutralized and expanded, the water absorbed by the crosslinked HA component and the crosslinked HA component is about 1: 1 by weight. The resulting hydrated HA-based gel has a highly coherent character.

The HA-based gel according to some embodiments of the present invention may have sufficient cohesion so that after centrifuging the gel for 5 minutes at 2000 rd / min the gel will not undergo substantial phase separation. In another embodiment, the gel is characterized by its ability to absorb at least one-fold of its weight, and when dilated with water at a gel / water weight ratio of about 1: 1, for example, The gel has sufficient cohesion to maintain its integrity.

The hydrated crosslinked HA gel can be expanded to achieve the desired cohesion. This step can be carried out, for example, by adding an aqueous solution containing an acid such as HCl to neutralize the cross-linked and hydrated HA gel. The gel is then expanded in a phosphate buffered saline (PBS) solution for a sufficient time and at a low temperature.

In one embodiment, the resulting swollen gel is highly cohesive without visible, apparent particles, e.g., without visible, visibly apparent particles when viewed by the naked eye. In a preferred embodiment, the gel has no visibly distinct particles upon magnification of less than 35 magnifications.

The gel is now purified by conventional means, such as dialysis or alcohol precipitation, to recover the crosslinked material, to stabilize the pH of the material, and to remove any unreacted crosslinking agent. Additional water or a slightly alkaline aqueous solution can be added to bring the concentration of NaHA in the composition to the desired concentration.

The pH of the purified, substantially pH-neutral, crosslinked HA gel is adjusted to be somewhat alkaline, preferably such that the pH of the gel is greater than about 7.2, for example, from about 7.5 to about 8.0. This step may be carried out by any suitable means, for example, by adding a suitable amount of dilute NaOH, KOH, NaHCO ₃ or LiOH to the gel, or any other alkali molecule, solution and / or buffer composition known to those skilled in the art And the like.

An effective amount of lidocaine, for example lidocaine HCl, is then added to the purified cohesive NaHA gel. For example, in some embodiments, lidocaine HCl is provided in the form of a powder that is soluble using water for injection (WFI). The gel is kept neutral by using a buffer or by adjusting with dilute NaOH so that the final HA / lidocaine composition has a preferred, substantially neutral pH. Preferably, the final HA-based filler composition comprising lidocaine will have a lidocaine concentration of at least about 0.1% to about 5%, such as about 2%, or in another example about 0.3%, of the composition.

After addition of lidocaine HCl, or alternatively, during the addition of lidocaine HCl, the HA / lidocaine gel or composition is homogenized to produce a highly homogeneous coherent HA / lidocaine gel with the desired consistency and stability. Preferably, the homogenizing step comprises mixing, stirring, or beating the gel with a controlled shear force to obtain a substantially homogeneous mixture.

The HA / lidocaine compositions described herein exhibit properties that depend on the nature of the composition and the presence of at least one anesthetic. The viscosity of the HA / lidocaine composition may be from about 50 Pa * s to about 450 Pa * s. In another embodiment, the viscosity is from about 50 Pa * s to about 300 Pa * s, from about 100 Pa * s to about 400 Pa * s, or from about 250 Pa * s to about 400 Pa * s, To about 250 Pa * s.

After homogenization, the HA / lidocaine composition is introduced into a syringe and sterilized. Syringes useful for use in accordance with the present invention include any syringe known in the art capable of delivering a viscous dermal filler composition. The syringe generally has an internal volume of about 0.4 mL to about 3 mL, more preferably about 0.5 mL to about 1.5 mL, or about 0.8 mL to about 2.5 mL. This internal volume is related to the inner diameter of the syringe, which plays an important role in the pressure output required to inject the high viscosity skin filler composition. The inner diameter is generally from about 4 mm to about 9 mm, more preferably from about 4.5 mm to about 6.5 mm or from about 4.5 mm to about 8.8 mm. In addition, the pressure output required to deliver the Ha / lidocaine composition from the syringe depends on the needle gauge. The gauge of the needle used generally comprises about 18G to about 40G, more preferably about 25G to about 33G or about 16G to about 25G. Those skilled in the art will be able to determine the exact syringe dimensions and needle gauge required to meet a particular pressure output requirement.

The pressure output exhibited by the HA / lidocaine composition described herein using the needle dimensions described above is the patient's pressure output at a comfortable scanning speed. "Comfortable to the patient" is used to define a scan rate that does not cause injury or excessive pain to the patient when injecting the soft tissue. Those skilled in the art will appreciate that "comfort" as used herein includes comfort or ability in injecting a HA / lidocaine composition, as well as patient comfort, as well as a physician or medical professional. While a predetermined pressure output can be achieved using the HA / lidocaine composition of the present invention, those skilled in the art will appreciate that a high pressure output makes control during the scan impossible and that such uncontrollability can cause additional pain to the patient I understand. The pressure output of the HA / lidocaine compositions of the present invention may be from about 8 N to about 15 N, or more preferably from about 10 N to about 13 N, or from about 11 N to about 12 N.

As used herein, sterilization preferably includes any method known in the art for effectively killing or eliminating a transmissible agent, without substantially changing the degradation of the HA / lidocaine composition .

One preferred method of sterilizing a filled syringe is by an autoclave. Autoclaving can be achieved by applying a combination of heat, pressure, and moisture to samples that require sterilization. Many different sterilization temperatures, pressures and cycle times can be used for this step. For example, a filled syringe can be sterilized at a temperature of at least about 120 [deg.] C to about 130 [deg.] C or higher. Water may or may not be used. In some embodiments, the applied pressure is dependent on the temperature used in the sterilization process. The sterilization cycle may be at least about 1 minute to about 20 minutes or more.

Other methods of sterilization include the use of gaseous species known to kill or kill infectious agents. Preferably, ethylene oxide is used as a sterile gas and is known in the art to be useful for medical equipment and products.

Other sterilization methods include the use of an irradiation source known in the art to kill or eliminate infectious agents. The irradiation beam targets the syringe containing the HA / lidocaine solution, and the wavelength of the energy kills or eliminates the unwanted infectious agent. Useful preferred energies useful herein include any other wavelengths or wavelengths that kill or destroy unwanted infectious agents without substantially altering the degradation of ultraviolet light (UV), gamma rays, visible light, microwaves, or preferably HA / lidocaine compositions Band, but is not limited thereto.

Providing a crosslinked HA-based gel (hereinafter sometimes referred to as a precursor gel) without anesthetic agent, adjusting the pH of the precursor gel to obtain a gel having a pH of about 7.2 to 8.0 and a suitable amount of lidocaine or other anesthetic agent A method of making an HA-based composition, generally comprising the step of adding to a pH-adjusted gel to obtain an HA-based composition comprising an anesthetic is also described. In one embodiment, the precursor gel is a highly coherent gel containing up to about 10% free HA by volume. In another embodiment, the precursor gel is a relatively less coherent gel comprising at least 10% to about 20% free HA by volume.

Example 1

Gel Cohesive  Test method for

The following tests can be performed to demonstrate the cohesiveness of HA-based gel compositions for the purposes of the present invention.

First, 0.2 g or 0.4 g of the gel composition to be tested is put into a glass syringe. Next, 0.2 g or more of phosphate buffer is added to the syringe and the mixture is thoroughly mixed for about 1 hour to obtain a homogeneous mixture. The homogenized mixture is then centrifuged at 2000 rpm for 5 minutes to remove air bubbles and allow any particles to decant. The syringe is then placed in the vertical position and a drop of eosin colorant is placed on the surface of the gel using the syringe and 18G needle. After 10 minutes, the dye slowly spread throughout the gel.

After dilution, homogenization and decanting of the gel, the relatively low cohesive gel exhibits phase separation (a dilute dew-pointed upper phase with no particles and a lower phase consisting of viscous or microscopically visible decanted particles). Under the same conditions, the highly cohesive gel does not substantially exhibit phase separation and the dye does not diffuse into the coherent formulation. On the other hand, relatively less cohesive gels exhibit distinct phase separation.

Example  2

Lidocaine  Have Soft tissue Filler  synthesis

NaHA fibers or powders are hydrated in an aqueous solution containing an alkaline solution, for example NaOH. The mixture is mixed at an ambient temperature of about 23 DEG C to form a substantially homogeneous alkali HA gel.

The crosslinking agent, BDDE, is diluted in aqueous solution and added to the alkali HA gel. The mixture is homogenized for several minutes.

Alternatively, BDDE can be added directly to the HA fiber (dry state) at the beginning of the process prior to hydration. The cross-linking reaction then begins relatively slowly at ambient temperature, ensuring much better homogeneity and crosslinking performance. See, for example, U.S. Patent No. 6,921,819 to Piron et al., Which is incorporated herein by reference in its entirety as if fully set forth herein.

The resulting crosslinked HA gel mixture is then heated at about 50 캜 for about 2.5 hours. The material is now a highly cross-linked HA / BDDE gel (mode = solid gel). The crosslinked gel is then neutralized with a suitable acidic solution. The neutralized HA gel is then expanded in a phosphate buffer at a cold temperature, for example, at a temperature of about 5 DEG C, to obtain a HA gel that is highly coherent. In this particular embodiment, the phosphate buffered saline solution contains water for injection (WFI), disodium hydrogen phosphate, and sodium dihydrogen phosphate. Upon neutralization and expansion, the crosslinked HA component and water absorbed by the crosslinked HA component are in a weight ratio of about 1: 1.

The coherent, expanded HA gel is then mechanically agitated, filled into a dialysis membrane and dialyzed against phosphate buffer. To remove the unreacted cross-linking agent, stabilize the pH close to neutral (pH = 7.2) and ensure the proper osmotic concentration of the HA gel, the HA gel is charged to the dialysis membrane and the bath is replaced for a maximum of several days While dialyzing against phosphate buffer. The osmotic concentration of the resulting coherent HA gel is between about 200 mOsmol and about 400 mOsmol, and most preferably about 300 mOsmol.

After dialysis, the resulting cohesive HA gel is substantially neutral in pH, preferably about 7.2, and there is no visible particles in the fluid medium when magnified at about 35 magnifications.

Lidocaine hydrochloride (lidocaine HCl) in powder form is first dissolved in WFI and filtered through a 0.2 탆 filter. A dilute NaOH solution is added to the coherent HA gel to reach a somewhat basic pH (e.g., a pH of about 7.5 to about 8). The lidocaine HCl solution is then added to the somewhat basic gel to achieve a final desired concentration, for example, a concentration of about 0.3% (w / w). At this time, the obtained pH of the HA / lidocaine mixture is about 7 and the HA concentration is about 24 mg / mL. Mechanical mixing is carried out in a standard reactor equipped with an appropriate blender mechanism to obtain proper homogeneity.

If desired, the appropriate amount of free HA gel can be added to the HA / lidocaine gel mixture, which has the advantage of increasing the rate of lidocaine delivery. For example, to obtain a homogeneous viscoelastic gel, free HA fibers are expanded in a phosphate buffer solution. This free HA gel is then added to the cross-linked HA / lidocaine gel (e.g., about 5%, w / w). The resulting gel is then filled into a ready-to-fill sterilized syringe and autoclaved at a temperature and pressure sufficient for sterilization for at least about 1 minute.

After autoclaving, package the final HA / lidocaine product and distribute it to the physician. Products made according to the methods of the present invention exhibit one or more stability characteristics as defined elsewhere herein. For example, the final autoclaved HA / lidocaine product has acceptable viscosity, cohesive and extrusion power. No degradation of the HA / lidocaine product occurred when the product was tested after storage for several months.

Example  3

Soft tissue Filler  characteristic

The properties of the HA / lidocaine compositions prepared according to the methods described herein are set forth in Table 1 below. For example, the pressure output may be measured using an INSTRON® Advanced Materials Testing System Model 5564, running BLUEHILL® software version 2.11 (Instron, Norwood, Mass.), (Instron, Norwood, Mass., USA).

HA / Lidocaine  Composition
Exterior Homogeneous and transparent gel pH 7.2 Pressure output  (N) 10.8 N NaHA  content 23.7 mg / g Sterility Sterile (SAL = 10 ^-6 ) Osmotic concentration 321 mOsml / kg Lidocaine  content(%) 0.29% 2,6- Dimethyl aniline  content coincidence

Multiple studies were conducted to ensure that product specifications were maintained throughout the shelf life of the composition. In addition, 2,6-dimethyl aniline content was measured to confirm that lidocaine was not degraded.

Table 2 provides a summary of stability test results for the compositions prepared as described herein.

HA / Lidocaine  Composition
exam 3 months results 6 months results 9 months results Transparent and homogeneous mode coincidence coincidence coincidence pH 7.2 7.2 7.2 The pressure output (N) 11.9 11.1 11.9 NaHA concentration (mg / g) 23.8 23.1 24.2 Sterility coincidence coincidence coincidence The osmolarity (mOsm / kg) 349 329 342 Lidocaine content (%) 0.29 0.29 0.29 2,6-Dimethyl aniline content coincidence coincidence coincidence

At 9 months (from date of manufacture), the composition was found to still meet product specifications.

Example  4

Kinetic emission ( Kinetic Release )

The following examples illustrate the release kinetics of lidocaine from cohesive HA gels according to the invention. The purpose of the examples is to demonstrate that the lidocaine contained in the HA gel according to the present invention is freely released from the gel when placed on the skin.

Dialysis was performed for different periods (about 10 g of the gel was placed in a small dialysis bag and then placed in 30 g of water). After each dialysis session was stopped at a given time, the gel was homogenized using a spatulaer and the amount of lidocaine was determined using the UV method. The final concentration of the dialysis vessel was in agreement with the theoretical concentration of lidocaine, indicating that lidocaine was released freely from the gel.

Table 3 shows the lidocaine concentration in% (w / w), which is the value of the released lidocaine and the calibration value of the measurement. 9 is a graph showing the results shown in Table 3 below. Figure 9 shows the theoretical equilibrium concentration of lidocain present when lidocaine is held in the gel or released freely. As indicated by the graph, the data suggest that lidocaine is liberated from the gel.

MMA3056 MMA4031-EC6 MMA4031-EC2 MMA4031-EC3 MMA4031-EC4 MMA4031-EC5 MMA4029-EC7 Dialysis time (h) 0 hours 1 hours
30 minutes 5 hours 7 hours 23 hours 48 hours 72 hours [Lidocaine]
(%) 0.29 0.20 0.16 0.15 0.08 0.07 0.07

Figure 1 shows that the concentration profile of lidocaine over time has reached equilibrium, which corresponds to the free release of lidocaine. In Figure 1, the formulation of the composition is a coherent, cross-linked HA gel. The composition has a HA concentration of about 24 mg / mL, a degree of crosslinking of about 6%, a G 'of about 170 and a high molecular weight HA to low molecular weight HA ratio of from about 95% to 5% to about 100% high molecular weight HA . In vitro studies show that lidocaine is liberated from the gel and is not retained in the gel once it is implanted.

Although the present invention has been described and illustrated with a certain degree of particularity, it is evident that the present disclosure is limited only by way of example, and that those skilled in the art will be able to devise numerous alternative constructions and constructions in the combinations and arrangements of parts without departing from the scope of the invention as hereinafter claimed .

Unless otherwise stated, all numbers such as, for example, molecular weights, reaction conditions, etc., used in the specification and claims are to be understood as being modified in all instances by the term "about. &Quot; Accordingly, unless stated to the contrary, the numerical parameters set forth in this specification and the appended claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalence to the scope of the present invention, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary approximation techniques. Although numerical ranges and parameters describing the broad scope of the present invention are approximations, numerical values describing specific embodiments are reported as precisely as possible. However, any numerical value originally includes a predetermined error necessarily arising from the standard deviation appearing in each test measurement.

Similar terms used in the context of singular terms ("a", "an" and "the") and in the context of describing the invention (in particular in the context of the following claims), unless otherwise stated or clearly contradicted by context, Should be construed to cover both the plural and the plural. The description of the numerical ranges in this specification serves only as a shorthand method of separately mentioning each individual value falling within that range. Unless otherwise stated herein, each individual value is included herein as if separately mentioned herein. All methods described herein may be performed in any suitable order, unless otherwise indicated or clearly contradicted by context. The use of any and all examples or exemplary expressions (e.g., "such as", "such as") provided herein is merely for illustrative purposes of the present invention, The month does not limit the category of. No representation in this specification should be construed as representing any undischarged element essential to the practice of the invention.

The grouping of alternative elements or embodiments of the invention disclosed herein should not be construed as a limitation. Members of each group may be mentioned and claimed individually, or in any combination with other members of the group or with other elements presented herein. It is contemplated that one or more members of the group may be included or removed from the group for reasons of convenience and / or patentability. Where any such inclusion or deletion occurs, the present specification is considered to include the group as amended and therefore satisfies the description of all Markush groups used in the appended claims.

Certain embodiments of the present invention, including the best modes found by the inventors in the practice of the present invention, are described herein. Of course, variations of the described embodiments will be apparent to those skilled in the art having read the foregoing detailed description. The inventor expects those skilled in the art to use these variations appropriately and the inventor wishes to make the present invention contrary to what is specifically described herein. Accordingly, the invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Furthermore, any combination of the above elements in all possible variations is included in the present invention, unless otherwise indicated or clearly contradicted by context.

In addition, numerous references have been made to patents and publications through this specification. Each of the above cited references and publications are incorporated herein by reference in their entirety.

The particular embodiments disclosed herein may be further limited in the appended claims using the terms "done" or "essentially consisting of". Whether appended as is, or by correction, or as used in the claims, the transitional term "comprising " excludes any element, step, or component not expressly listed. The transitional term "consisting essentially of" limits the scope of the claims to those that do not materially affect the particular material or step and the basic novel characteristic (s). The embodiments of the invention thus claimed are inherently or clearly described and made possible in the present specification.

Finally, it should be understood that the embodiments of the present invention are illustrative of the principles of the invention. Other modifications that may be used fall within the scope of the present invention. Thus, by way of example and not limitation, alternative forms of the present invention may be used in accordance with the teachings herein. Therefore, the present invention is not strictly limited to what is shown and described.

Claims (11)

Butadiene diglycidyl ether (BDDE), 1,4-bis (2,3-epoxypropoxy) butane, 1,4-bisglycidyloxybutane, 1,2-bis Hyaluronic acid (HA) crosslinked with at least one crosslinking agent selected from the group consisting of 3-hydroxypropyl (meth) acrylate, 3-epoxypropoxy) ethylene and 1- (2,3-epoxypropyl) ) Component;
Neutralizing the cross-linked HA component by adding an acid-containing aqueous solution;
Expanding the crosslinked HA component in a phosphate buffered aqueous salt solution;
Adjusting the pH of the HA component to 7.5 to 8.0; And
Adding a solution containing at least one anesthetic agent to the HA component having the adjusted pH to obtain a HA-based soft tissue filler composition,
Wherein the HA component comprises 10% to 20% by weight of non-crosslinked HA relative to the total composition. delete 8. The method of claim 1, wherein the at least one anesthetic is lidocaine. 3. The method of claim 1, wherein providing the HA component comprises providing a dry non-crosslinked sodium hyaluronate (NaHA) material and a non-drying, non-crosslinked NaHA gel by hydrating the crosslinked NaHA material in an alkali solution ≪ / RTI > 5. The method of claim 4, wherein the alkali, non-crosslinked NaHA gel has a pH of about 8.0. 5. The method of claim 4, wherein the alkali, non-crosslinked NaHA gel has a pH of about 10. delete delete The method of claim 1, wherein the HA component has a degree of crosslinking of 2% to 5%. 2. The method of claim 1, wherein the HA component comprises particles of crosslinked HA having an average particle size of from 200 [mu] m to 250 [mu] m. delete

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